THE ROMANCE OF SEED-SOWING. 145 



American Eartli-nut {Arachis hypoc^ca), the ' nut,' so called — in 

 reality a pod — ^is buried while still unripe, and later on, under- 

 ground, developes its two seeds. If the burial for any reason be 

 not made, the pod withers, and no seeds are produced. 



Some cases exist in wliich moviinent of the sted itself, after it 

 has left its capsule, either scatters or buries it. The seed of 

 \Vood-sorrel {Oxalis) ruptures its testa or coat, expelling the 

 body of the seed with violence. The Stork's-bills, belonging 

 to the Geranium Order, possess seeds which develope a 

 Iiairy, twisted ' awn,' which, under given conditions, principally of 

 moisture, unrolls and pushes the seed down into the ground, the 

 awn itself being kept fixed by surrounding herbage. 



Stipa pennata, a pretty European Grass, has seeds with a 

 corkscrew rod and long feather springing from their apex ; the 

 whole arrangement is over a foot long, and in moist weather the 

 unrolling of the rod acts as in the Stork's-bill seeds, the feather 

 probably serving the purpose of carrying the seed, first of all, to 

 its resting-place. 



The elaters, contractile filaments forming part of the spores 

 of the Horsetails, act in somewhat similar manner, by fixing the 

 spores to the earth, and in some water-weeds the spores are 

 furnished with vibratile cilia or fine hairs, enabling them to 

 move in the water spontaneously, and so disseminate them- 

 selves. 



We have now seen the various agents and contrivances by 

 which seeds are placed in favourable situations for growth, and 

 we cannot fail to be struck with the wonderful adaptation and 

 ingenuity of many of them. That the wings, or the hooks, as the 

 case may be, are not mere accidents or ornaments, as some would 

 have us imagine, but exist for the purposes named, is, I think, 

 fixirly established by looking at the kinds of plants on which they 

 are found, and considering their stature. Sir John Lubbock, in a 

 most interesting paper in the Fortnightly for April, 1881, gives us 

 the two following statements (I quote them in outline only) : — 



I.—" Roughly speaking, there are some 30 genera, belonging 



to 21 different Orders, having seeds or fruits with wings. They 



are all trees or climbing shrubs ; not one is a low herb. That 



is, they all occur in situations where the wind has free access to 



New Series, Vol. I. l 



1888. 



